Radio-Frequency Heating Control
Radio-frequency systems heat plasma by launching electromagnetic waves tuned to particle resonances, and each system regulates power, frequency, and coupling.
Wave heating families
Radio-frequency heating covers several bands named for the resonance they exploit: ion cyclotron (tens of megahertz), lower hybrid (around a gigahertz), and electron cyclotron (tens to over a hundred gigahertz). Each launches a wave from an antenna or launcher, the wave propagates into the plasma, and it deposits energy where the local field and density bring it into resonance.
Common control tasks
Every radio-frequency system regulates the generator output power, protects the source and transmission line against reflected power, and manages coupling of the wave into the plasma. Because the plasma edge changes during a pulse, the coupling changes too, and the controller must keep power flowing forward without over-stressing the source with reflections.
Deposition steering
A strength of radio-frequency heating is localized, steerable deposition. Electron cyclotron beams can be aimed by movable mirrors to hit a chosen flux surface, useful for suppressing instabilities. Control couples the launcher aiming to real-time plasma measurements so power lands where it is wanted, for example on a magnetic island to stabilize it.
- Regulate generator forward power
- Protect against reflected power from changing coupling
- Steer deposition to a target plasma location
- Modulate power for heating, current drive, or stabilization
In Kronos designs
Auxiliary heating and current-drive systems, including radio-frequency schemes, appear in the Hyperion breeder scenario that reaches a modeled Q of 3.424. The specific mix is a design choice within a simulation; no net-gain hardware claim is made before the first-of-a-kind machine produces first tritium, targeted around 2030 in the program plan. The control descriptions here are general engineering behaviour.
The dedicated pages on electron and ion cyclotron control cover the band-specific hardware and interlocks.